1. Field of the Invention
This invention relates to an air conditioner, and more particularly to a unitary heat exchanger used for an air conditioner.
2. Prior Arts
Conventional heat exchangers used for the air conditioner, for instance as disclosed in Japanese Utility Model Publications No. SHO 62-36029 or SHO 63-11553 has a construction as shown in FIG. 4. That is, air from a room introduced through an inlet 5 is mixed with a fuel which is injected by a burner motor 4 mounted on a support panel 7.
The mixture of the air and the fuel is introduced into a combustion furnace 2 through a burner 6 and a connecting duct 8 and becomes incinerated therein. Upon the combustion operation, the generated combustion gas with high temperature is moved up through the heat exchanger 1 composed of a plurality of pipes juxtaposedly arranged therebetween. Then, the combustion gas is flowed into a warm air chamber 11, and discharged to the outdoor through an outlet 3 of the exhaust pipe(not shown). Here, the room air supplied by a blower(not shown) is heated during passing through the heat exchanger 1 in the form of heat convection.
Meantime, in the conventional heat exchanger constructed as above, the heat exchanger 1 and the combustion furnace 2 are installed in parallel, which increases the volume and weight of the heat exchanger 1, whereby the air conditioner can not be smaller in size. Also the air intake motor becomes larger to increase the power consumption, which is not economical. Moreover, the heat exchanger 1 is connected to the combustion furnace 2 through the connecting pipe 9, thereby the flow path of the hot combustion gas from the combustion furnace 2 to the heat exchanger 1 is long and complex. As a result, there arises a problem that it takes too much time for the hot combustion gas to be supplied to the heat exchanger 1, which deteriorates the heat exchanging efficiency at the heat exchanger 1.